Deprecation warning due to invalid escape sequences

[tirkarthi]

Deprecation warnings are raised due to invalid escape sequences. This can be fixed by using raw strings or escaping the literals. pyupgrade also helps in automatic conversion : https://github.com/asottile/pyupgrade/

find . -iname '*.py' | grep -Ev 'vendor|example|doc|sphinx' | xargs -P4 -I{} python3.8 -Wall -m py_compile {}
./easygui/boxes/utils.py:132: DeprecationWarning: invalid escape sequence \[
  res = re.search('(?<=\[).(?=\])', text)
./easygui/boxes/utils.py:140: DeprecationWarning: invalid escape sequence \[
  res = re.search('(?<=\[\[).(?=\]\])', text)
./easygui/boxes/utils.py:148: DeprecationWarning: invalid escape sequence \[
  res = re.search('(?<=\[\<).+(?=\>\])', text)
./easygui/boxes/button_box.py:360: DeprecationWarning: invalid escape sequence \d
  m = re.match("(\d+)x(\d+)([-+]\d+)([-+]\d+)", self.boxRoot.geometry())
./easygui/boxes/filesave_box.py:35: DeprecationWarning: invalid escape sequence \*
  """
./easygui/boxes/fileopen_box.py:29: DeprecationWarning: invalid escape sequence \*
  """